Demands for higher data rates for mobile services are steadily increasing. At the same time modern mobile communication systems as 3rd Generation systems (3G) and 4th Generation systems (4G) provide enhanced technologies, which enable higher spectral efficiencies and allow for higher data rates and cell capacities. The demands are growing for both directions of transmission, i.e. for the DownLink (DL), i.e. for transmission from the network infrastructure to a mobile transceiver, as well as in the UpLink (UL), i.e. in the direction from a mobile transceiver to the network infrastructure.
Conventional mobile communication systems make use of circuit switched and packet switched data. While for circuit switched data transmission radio resources are permanently reserved in a connection oriented manner, packet data transmission makes use of scheduling, i.e. radio resources are assigned non-permanently in a connection less manner. The procedure of assigning radio resources to certain users for packet data transmission is also referred to as scheduling. The entity carrying out scheduling is also called a scheduler.
At the same time data services become more and more diverse. In other words, the diversity of the Quality of Service (QoS) requirements is steadily growing. While modern mobile terminals use applications which generate background traffic, i.e. packet switched traffic of rather low amounts, which may or may not be delay sensitive, other applications such as voice and video services generate large amounts of data with high quality demands.